I had a really similar experience when I was in high school, though I didn't get expelled. I made a website with photos of students (and their first names) giving the finger to the camera. People of course set this as the home page on library computers.

Unhappily, this was right after Columbine, so the administration was super paranoid and I was a little X-Files-obsessed black-trenchcoat-wearing weirdo... so I got a week's suspension.